McLaren’s three-seat successor to its F1 supercar aims to at least match that legend’s top speed from 20 years ago. The floor is set: 243 mph.

The as-yet-unnamed BP23, a gas-electric hybrid “Hyper-GT” touted to be both “the fastest-ever and the most luxurious McLaren,” will be able to “exceed 243 mph,” the company said. It will be the next model in McLaren’s Ultimate Series after the 2019 McLaren Senna, with a reveal set before the end of the year.

That “fastest-ever” claim may wear an asterisk, depending on whether McLaren uses a modified, one-off version to set the fastest possible speed. There’s precedent, since the F1’s reign as the world’s fastest production car—a title it held from 1998 until the 253-mph Bugatti Veyron broke it in 2005, with us behind the wheel—isn’t without disclaimers.

When we tested one of the first F1s in our August 1994 issue, the then-$815,000 supercar pegged its 7500-rpm rev limiter at 221 mph. A year prior, using an earlier prototype, McLaren clocked 231 mph at Italy’s Nardo circuit. Then in 1998, McLaren went all-out at Volkswagen’s Ehra-Lessien test track, removing the rev limiter and fitting taller gears for an insane 240.1-mph official record, as averaged from runs in opposite directions. The best run on the 5.4-mile straight—242.956 mph—is what McLaren is gunning for with the BP23, even though stock F1s couldn’t have approached that speed on the same track.

These are technicalities, but technicalities win headlines and customers. It’s a longer way still to beating the Koenigsegg Agera RS, which in November set a 277.9-mph two-way run on a closed 11-mile stretch of Nevada highway. All 106 examples of the BP23 that McLaren plans to build are already sold (at over £1.6 million each) and they’re to be manufactured late next year, which should make them 2020 models. It will be at least that long before anyone knows just how fast the final production model can go.